Nikon N90 Exposure control, Fill-flash, Focus-Priority for autofocus, Flash synchronization

Exposure control

Programmed auto: Camera sets both shutter speed and aperture for correct exposure.

Shutter-Priority auto: User selects shutter speed and camera sets matching lens aperture for correct exposure.

Aperture-Priority auto: User selects aperture and camera sets matching shutter speed for correct exposure.

Manual: User selects both shutter speed and aperture, following or ignoring the meter'srecommendations (by LCD readout) to achieve the desired exposure.

Fill-flash

A method of flash photography which combines flash illumination and ambient light, but does not necessarily attempt to balance these two types of illumination.

Focus-Priority for autofocus

Shutter cannot be released until subject is in focus. Suitable when in-focus subject is important.

With N90 camera body, Focus-Priority is given to Single Servo AF mode while Release-Priority is given to Continuous Servo AF. However, the Electronic Organizer can change priority to perform Release-Priority Single Servo AF or Focus-Priority Continuous Servo AF.

Flash synchronization

The timing of the flash so it fires coincident with the operation of the camera'sshutter. There are two types of synchronization: Normal Sync which fires the flash at the start of the exposure, and Rear Sync which fires the flash at the end of the exposure.

f-number

The numbers on the lens aperture ring and on the N90'sLCD which indicate the relative size of the lens aperture opening . The f-number series is a geometric progression based on changes in the size of the lens aperture, as it is opened and closed. As the scale rises, each number is multiplied by the factor 1.4. The standard numbers for calibration are 1.0, 1.4, 2, 2.8,4,5.6,8, 11,16,22,32, etc., and each change results in a doubling or halving of the amount of light transmitted by the lens.

Hyperfocal distance

The closest point a photographer can focus on where the depth of field includes infinity. When the lens is focused for hyperfocal distance, the deepest depth of field, covering from 1/2 the hyperfocal distance to infinity, can be obtained at each f/stop. The longer the focal length, the longer the hyperfocal distance; the smaller the aperture (the larger the f/number), the shorter the hyperfocal distance.

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